—on the condition that he will return two sacks of maize, or even three sacks, after the harvest; or that he will give, for instance, ten pounds on the understanding that he must deliver a sack of maize at harvest time, bearing in mind that a sack of maize currently costs one hundred pounds. In short, every loan is expected to bring back double or even triple its amount. What is the ruling on this kind of transaction? And what is the religious judgment concerning these people who exploit their weak brethren through such dealings—are their actions lawful or forbidden?

Answer: Concerning the first part of the question, where one gives him a single sack of maize on the condition that he repay two sacks after a period of time, this is impermissible, for it is ribā; it combines both ribā al-faḍl and ribā al-nasīʾa. Therefore it is absolutely unlawful when treated as a sale or exchange.

As for the latter part of the question, where he hands over cash in return for maize to be delivered at a later date, there is no harm in that. This is what is called a salam credit sale: the price is paid in advance while the commodity is deferred. It is permissible according to the Sunnah of the Prophet, peace and blessings be upon him, and is known as a salam debt.

With regard to the wealthy person who multiplies and enlarges his profit at the expense of the poor—giving him a small amount of money and then, when the term falls due, taking from him a great deal of food, more than double the original amount—this is not befitting. One should not exploit the need of the poor or burden him with excessive increases. Rather, any surplus should be reasonable: enough to benefit the rich lender without causing the poor borrower undue hardship.